US2386962A - Printing machine - Google Patents

Description

Oct. 6, 1945- c. L. LOW 2,386,962

PRINTING MACHINE Filed Aug. 7, 1943 5 Sheets-Sheet l INVENTOR. 671092456 4. 4 on/ Oct. 16, 1945.

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PRINTING MACHINE Filed Aug. 7, 1943 5 Sheets-Sheet 5 I N V EN TOR. B 624%;[5 A 40W mflfiaww Patented Oct. 16, 1945 UNITED STATES PATENT was PRINTINGHACEINE OFFICE Charles L. Low, Lee Township, Allegan County, Mich. Application August 7, 1943, Serial No. 497,738

9 Claims. (c1. 101-252) This invention relates to improvements in printing machines. i

The main objects of this invention are:

First, to provide a novel and improved method for printing indirect or offset impressions from a relief or letter press form.

Second, to provide a printing method of the type .described for offset printing from a conventional type form in which the final impression is characterized by its clarity and sharpness and in which the need for make-ready, patching and like work is eliminated.

Third, to provide a machine for producing oilset printing impressions from a letter press or relief type form or relief printing surface in which the form is quickly and easily set up and impressions produced therefrom without requiring extensive preliminary work, make-ready, patching and the like.

Fourth, to provide a flat bed or bed and cylinder machine adapted to print oifsetimpressions from a form of the type described.

Fifth, to provide a combinationof offset or transfer members or surfaces, a. printing form, inking mechanism and a printing cylinder for printing ofiset impressions of the type described which is well adapted for incorporation in known types of flat bed or bed and cylinder printing machines.

Further objects relating to details and economies of the invention will appear from the description to follow. the claims.

A structure embodying the features of this invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view illustrating a printing machine suitable for performing the method of the invention, certain parts of the sheet feeding mechanism having been removed to clarify the arrangement of parts of the press.

Fig. 2 is an enlarged, fragmentary, perspective view from the side of the press oppositethat shown in Fig. 1, further illustrating certain features thereof embodied in the invention.

Fig. 3 is a fragmentary top plan view of the press according to the invention, certain parts thereof not germane to the invention having been removed in order to facilitate an understanding of the structure of the press and the printing method performed thereby.

Fig. 4 is an enlarged, fragmentary view in tical section, on line 4-4 ofFlg. 3, longitudinally therewith.

, of the press illustrating the operating connections The invention is defined in ver- Figs. 5 and 6. are enlarged. fragmentary views illustrating diagrammatically the operation of the present press in opposite relative movements of the bed and printing cylinders thereof.

Fig. 7 is a fragmentary view in side elevation illustrating the cylinder elevation control instrumentalities incorporated in the press.

Fig. 8 is a fragmentary conventional view il lustrating the layout in coacting relation with the roll lowering means.

Thi invention relates generally to a method of printing an indirect or oflset impression from an ordinary letter press or relief type form, and to a flat bed or bed and cylinder rolling contact press for performing the invention. It will be understood'that ordinary printer's type face is negative-or reversed, as are of course all ordinary relief printing plates employed in relief printing processes. This of course prints a positive impression.

The present invention contemplates a method and apparatus for producing a positive impression from such a relief or letter press form by offset printing and the method and apparatus to be hereinafter described have provision for enabling this to be done without extensive preliminary work, make-ready, patching and the like. Moreover, the final printed impressions are characterized by uniform clarity and sharpness, and such uniformly sharp impressions are possible regardless of slight differences in the elevation of various parts of the original printing surface. The provisions for performing the method of the invention are well adapted for incorporation in a well known type of rolling contact bed and cylinder machine with certain changes therein.

In the drawings, wherein there is illustrated a horizontal reciprocating flat bed type machine suitable for the purposes of the invention, the reference numeral I in general indicates a frame provided with spaced, parallel, horizontal ways in which a flat reciprocable bed 2 is slidably mounted (Fig. 4). The frame has a superstructure 8 extending above the same providing secondary ways in which the roller carriage t is likewise mounted for horizontal, reciprocatory. sliding movement. There is not illustrated in detail the way or guide structure for mounting the bed and carriage for the movements described, inasmuch as presses having provisions to this end are well that the movements. of the bed, which carries the original ty an inking surface, to. be hereinafter described,

known. It will suflice tom form, a transfer'surface and,

designates a conventional inking structure in cluding a fountain 6 and fountain roll I journaled relative thereto. This roll is intermittently rotated during the operation of the press bra conventional age not necessary to describe in detail. For coaction with the roller there is provided a ductor 8 which is pivoted on the frame at 9. The ductor is oscillated to and from the fountain roll to apply ink to aflat inking plate I!) carried by bed 2 in the reciprocation thereof. The bed also has suitably locked thereon by means of blocks, quoins and the like, a letter press printing form ll of the character referred to above and an offset or transfer member I2 having a flat resilient offset surface l3, to be hereinafter referred to. The printing form II and transfer member I2 are mounted on the bed in spaced relation longitudinally of the press as illustrated in Fig. the bed being illustrated in its extreme lefthand position in that figure.

Form ll receives ink from the inking plate It by means of a pair of form inking'rollers l4 journaled in a suitable reciprocating carriage l5 which is slidably mounted on the press frame in an appropriate manner. Rollers l4 pick up ink from plate III by rolling thereacross, and the ink is distributed on rollers l4 by means of a reciprocatory vibrator roller l6 which is journaled in frame l5 and rides on rollers 14. Roller I6 is vibrated longitudinally of rollers I4 and transversely of the press by means of any well known reciprocating device. The ink deposited on inking plate In by ductor 8 is worked up and distributed thereon by a pair of angled distributor rollers ll mounted in forks on the frame.

Prior to further describing the printing operation in detail, the mechanism for producin the operative movements of the various reoipro-' eating parts of the press will be explained. This structure is illustrated in Fig. 4. The reference numeral 18 designates a pulley appropriately journaled on the frame and driven by a belt l9 from a further pulley on the shaft of a suitable motor I90, likewise mounted on the frame. Pulley' l8 rotates shaft 20, to which is secured a pinion 2| meshing with a large gear22 joumaled on the frame. This gear rotates a shaft 23 on which is secured a crank .24, said crank being drivingly connected by means of a rearwardly extending connectingrod 25 with an oscillating 1 pitman 26 which" pivoted 'at'2l to the frame.

At its upper end e pitman is drivingly conthe press for reciprocating movement longitudinally of the latter and carries at its rear end an inclined cam element 34 which is engageable with a roller 35 on an arm 35 secured to the ductor roll supporting arm Iii. Accordingly, as the cam and roller engage, the ductor 8 will be swun from the fountain roller'l forwardly into engagement with the inking plate III to deposit a quantity of ink on the latter.

Intermediate the mid-point of pitman 25 and the pivot 21 thereof the latter has rearwardly extending connecting rod or link 31 pivoted thereto, the extreme and of this connecting rod being in turn pivoted to the downwardly extending end 38 of the lever 39 which is pivoted on the frameat 40. Lever 89 extends upwardly and at its upper extremity pivotally carries a forwardly extending link 4| which is pivoted to the inkingroller carriage l5. Accordingly as pitman 26 is oscillated by crank 24 and connecting rod 25, it will be appreciated that the bed 2 and slide 32 are reciprocated simultaneously in the same direction, and that the form inkin roller carriage 15 will be reciprocated in the 0D- posite direction to pick up ink from plate It) traveling therebeneath and apply the same to the form H. The magnitude or amplitude of the reciprocable movement of carriage I5 is much less than that of the bed, because of the greater are of swing of pitman 26 at the bed connection than at the inking roller carriage connection.

For producing reciprocation of the cylinder carriage 4 simultaneous with the reciprocation of bed 2 but in the opposite direction an arrangement is utilized generally similar to that illustrated and described in the patent to Vierengel, No. 1,072,883, of September 9, 1913. This is not shown herein in great detail, but consists of an elongated rack 42 carried by and reciprocable with the bed on the frame (and effective to ro- 40 tate the two printing cylinders to, be hereinafter rack 46 fixed to thepress frame. As illustrated "bythe reciprocating carriage! andthe-manner described). A rack 42 is provided at either side of the bed and these racks mesh with gears 43 mounted on a shaft 44 which is rotatably journaled at 44' in the reciprocable cylinder carriage 4. This shaft also has secured thereto at opposite ends thereof a pair of smaller pinions-li;

which are in mesh with the teeth of stationary in Fig. 4; the rack 46 extends parallelftdand above the reciprocating rack 42. From the fore-'- going it will be-appreciated that as rack is reciprocated with the bed by the'instrumentali-'g ties discussed above, it causes rotative or osci1-.. lating movement of gears 13. However,-- the smaller pinions '45 are, like gears 43, secured to shaft 44, hence rotatable with gears 43, so, that as a result pimons 45 are caused to advance relative to the :jflxed stationary rack lit-with which they mesh. thereby advancing 'cylinder' opposite the direction carriage l in a direction of advance of bed 2.

There will now be described the rotatable printing membersorcylinders which are carried in which they coact with-(the letter press type form I] and transfer member 12' in performing the printingopeiation' in accordance with-the invention. members "consist of an offset cylinder 41. h n r il-onset blanket 48 mounted thereon and an impression" or printing cylinder 3 "having a conventional tympan sheet 50 thereon. This y nder likewise has associated therea with a suitable conventional gripper device 5|.

(Figs. land-3) Icoacting with any desired automatic or semi-automatic sheet feeding mecha impression.

assassa I nism at the feed end of the press for properly receiving and securing the sheets 52 to the im- The shafts I3, 54 of the offset and impression cylinders 41, 4! respectively are each integrally provided with an eccentric 55 extending the length of the respective cylinders 41, 49, said cylinders being rotatable on these eccentrics in the operation of the press. At their ends shafts 53, 54 are carried in adjustable bearing blocks .55 on the cylinder carriage 4. The purpose of the aforesaid eccentric arrangement is to enable the cylinders 41, 49 to be elevated and lowered relative to the bed during the operation of the press, thereby enabling the offset cylinder 41 to engage the type form and offset surface It in one direction of movement of the cylinder-carriage and i pression cylinder 4!.

to be elevated out of engagement therewith on the opposite movement. Likewise, it is necessary that the impression cylinder 49 cause the sheet to be printed to roll over offset surface IS in the operative stroke of the cylinder carriageand to be elevated thereabove on the return stroke, so as to pass out of contact with said surface when no sheet to be printed is carried thereby.

The angular position of shafts 53, 54, hence of the eccentrics 55, is controlled by the tappet arms 55, 59 secured to the shafts 53, 54 respectively, externally of the bearing blocks. Tappet arm 55 has an internally directed lug 60 which is engageable with a fixed tappet 6| on the frame superstructure 3. The tappet arms 58, 59 are also provided with externally extending lugs 62, 63

respectively, engageable with adjustable tappet fingers 64, 65 respectively, which are secured to a rock shaft 86 extending longitudinally parallel to the side of the frame and .iournaled in brackets 81 thereon (Figs. 1 and 7). Tappet finger 64 is provided with an adjusting screw 6 having a I lock nut 642 thereon. This adjusting screw regulates the lowering of the transfer cylinder 41 to conform with the size and character of the type-form Ii.

Shaft 65 has a laterally projecting rocker arm 68 secured thereto, this arm being interconnected by a rigid link 68 with one end of a cam follower lever ill pivoted on the press frame at H. The other end of this lever has a roller follower l2 thereon which is urged into engagement with a cam I3 rotatably mounted on the frame by means of a resilient tensioning member 14 secured to the frame and lever. Cam 13 is synchronized in its rotation with the reciprocatory movements of the bed and cylinder carriage,- being rotatably actuated in any suitable manner from the main press shaft 23, and as the cylinder carriage reciprocates past the fingers shifted by shaft 66 into and out of position for engagement with the lugs 52 and 53. It will be noted that the arrangement of the cylinder journalling eccentrics 55, 55 is such that, with the respective cylinders in operative, lowered bed engaging position, the angular thrust on the cylinder tends to urge the eccentrics further and maintain the same in the cylinder lowering direction. This insures an effective printing contact of the printing members at all times, resulting in uniform clarity and sharpness of the final 4 angular movement of the shafts with stops 133 on the carriage. This position limits the angular 64, 65 the latter are r by cam 13 and elements actuated adjustment of the eccentric shafts in either direction. Coiled thrust springs 134 coact with collars III and the carriage to take up lost motion and assist in oscillating the eccentrics, and said springs 134 through a toggle-like action. as apparent from Fig.2, operate to yieldingly retain the offset and the impression cylinder in either a depressed or an elevated position. The collar onthe impression cylinder eccentric shaft has an inwardly extending tappet lug I35 coacting with a fixed tappet 136 on the superstructure I to elevate the impression cylinder for the return or non-printing stroke.

' The transfer and impression cylinders 41, 49 are each provided with gears 15, 15 respectively, meshing with the reciprocating rack 42 as the latter is reciprocated to positively oscillate or rotate the cylinders. These gears are of a conventional split type, the parts of which are adapted to be angularly adjusted relative to one another to take up any lost motion in their meshing engagement with the rack. The form inking rolls l4 are positively driven by the reciprocating vibrator Hi, this vibrator being driven through the agency of a gear thereon meshing with an idler which is in turn in meshing engagement with rack 42 on the bed.

In operation, let it be assumed that the bed and cylinder are moving in the direction of the arrows in Fig. 5. This is the return or non-printing stroke, in which offset cylinder 41 rolls over the form to pick up an impression therefrom. It has been placed in this lowered position by the engagement of control lug 62 with tappet 54 at the end of the preceding printing stroke. Cylinder 4'! rolls over offset surface l3 during the re turn stroke to transfer its impression to the latter and after this happens the offset cylinder con-- trol lug 60 engages the fixed lug iii to elevatepression cylinder 40 for the succeeding printing stroke, OiTset cylinder control lug 60 has previously engaged fixed tappet 6| on the return stroke to elevate the offset cylinder subsequent to its passage over offset surface it, so that on the printing stroke the impression cylinder alone contacts the impression bearing offset surface It. The impression cylinder never engages form H.

Thus it will be understood that the two fixed tappets till, 736 operate to elevate cylinders M, M respectively, and the rockable tappets- M, 55 perform the lowering operation. These latter are rocked approximately in timed relation to the bed and carriage reciprocations so as to accomplish the aforesaid transfer engagements and disengagements in the manner described above,

thereby.

The foregoing cycle is repeated on each printing and return stroke of the bed and cylinder carriage relative to one another, the offset blanket 48 picking up a positive impression from the negative letter press type surface, transferring the same in reverse or negative to the fiat offset surface l3, and the sheet on cylinder 49 receiving a positive offset impression therefrom. This impression is of uniform distinctness and sharpness; a washed-out, gray impression is impossible, and it is possible to set up quickly and without trial and error procedure subsequent thereto as by patching and the like, to enable a satisfactory impression to be had. The cylinders are positively driven at all times and no difllculty with blurring, smearing or the like is experienced. The press may be operated at very high speeds with uniformly satisfactory results.

In Fig. 3 the various successive impressions taking place in the printing cycle are illustrated. Thus the reverse or negative type face of form I l is shown, the positive impression printed thereby, on offset blanket 48, the reverse or negative impression picked up therefrom by fiat offset surface [3, and the final positive impression offset onto sheet 52 from this surface. Of course, it will be appreciated that the sheet would never be found in printed form at the feed end of the machine. The parts have been arbitrarily arranged in positions shown solely for the purpose of graphically describing the above successive operations. The provisions of this invention have been illustrated in association with a horizontal bed machine. However, it will be apparent that the inventive features are equally applicable to either a vertically or angularly arranged type machine, hence it is desired that the invention be not regarded as unduly limited in this respect.

An embodiment of the invention which incorporates the principles of the invention in a highly desirable manner has been illustrated and described, although it is clear that other embodiments withinthe intent of the invention will suggest themselves to those skilled in the art. It should be understood that the foregoing terminology is used only descriptively rather than in a limiting sense, and with full intention to include equivalents of the features shown and described, within the scope of the following claims.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In a bed and cylinder machine having a frame supporting a bed and a cylinder carriage simultaneously reciprocable in opposite directions, a relief type form and a flat offset surface on said bed in spaced relation to one another longitudinally of the direction of reciprocation, an offset cylinder rotatably mounted on said carriage having a resilient offset surface thereon engageable with said form and bed ofiset surface in one direction of relative reciprocation of the bed and carriage whereby to pick up an impression from said form and transfer the same to said bed oflset surface, an impression cylinder rotatably mounted in said carriage and engageable with said bed offset surface in the opposite relative direction of reciprocation, said impression cylinder having means to secure a sheet thereon whereby the sheet picks up an impression from said bed offset surface, and means synchronized with the relative reciprocation of said bed and carriage for successively varying the vertical relationship of said cylinders to the bed as the relative reciprocation of the bed and carriage proceeds.

2. A machine for printing oflfset impressions from a negative type form, comprising a frame, a horizontal reciprocable bed carried by said frame having a relief type form and a flat oflset surface thereon in longitudinally spaced relation,

carriage in timed relation, a transfer cylinder rotatably mounted on said carriage, an impression cylinder rotatably mounted on said carriage, means for positively rotating said cylinders as the bed and carriage are reciprocated relative to one another, means for vertically shifting said cylinders relative to said bed in the reciprocation thereof, and means for synchronizing said last named means with the movements of the bed and carriage to rollingly engage the offset cylinder with said form and offset surface in one relative direction only of the reciprocation of the bed and carriage and to rollingly engage the impression cylinder with said offset surface only in the other direction.

3. A machine for printing offset impressions from a negative type form, comprising a, frame, a bed carried by said frame having a relief type form and a fiat offset surfacethereon in longitudinally spaced relation, a cylinder carriage, means for reciprocating-said bed and said carriage in opposite directions, a transfer cylinder rotatably mounted on said carriage, an impression cylinder rotatably mounted on said carriage, means for positively rotating said cylindersas the bed and carriage are reciprocated relative to one another, means for relatively shifting said cylinders andbed in reciprocation thereof, and means for synchronizing said last named means with the movements of the bed and carriage t0 rollingly engage the offset cylinder with said form and offset surface in one relative direction onlyof the reciprocation of the bed and carriage and to rollingly engage the impression cylinder with said offset surface only in the other direction.

,4. In a printing machine for printing offset impressions from a relief printing form, in combination with a reciprocable bed having thereon a flat printing form of the above type and a flat offset surface, said bed travelling successively in opposite directions on printing and return strokes constituting a single printing cycle, a rotatable sheet carrying impression cylinder and a rotatable transfer cylinder mounted adiacent said bed and traversed by the latter in the reciprocation thereof, said offset cylinder including a resilient compressible offset blanket rollingly engageable with the form and compressible during said engagement to compensate for differences in the height of the printing surfaces on said form, means for inking said form in the reciprocation of the bed, said ofiset surface and form traversing said offset and impression cylinders respectively in the order named on the printing stroke, means controlled by the reciprocation of said bed for elevating the offset cylinder out of engagement with the form and offset surface and for relatively positioning the impression cylinder for rolling engagement of a sheet thereon with said offset surface on said printing stroke, and means controlled by the reciprocation of the bed for elevating the impression cylinder relative thereto out of engagement with said oflset surface andloweringthe offset cylinder for rolling engagement with the form during the return stroke, whereby a complete printing cycle is'pera cylinder carriage simultaneously'reciprocable on saidframe with said bed in a direction opposite the directionof reciprocation of the bed thereon, means for reciprocating said bed and formed in the printing and return strokes, said offset cylinder receiving an impression from the form on the return stroke and transferring said impression to said offset surface, the sheet on said impression cylinder receiving an impres-V,

sion from said surface on the printing stroke duringwhich the offset cylinder is elevated relative to said surface.

5. In a printing machine for printing offset impressions from a relief printing form, in combination with a reciprocable bed having thereon a flat printing form of the above type and a flat offset surface, said bed travelling successively in opposite directions on printing and return strokes constituting a single printing cycle, a rotatable sheet carrying impression cylinder and a rotatable transfer cylinder mounted adjacent said bed and traversed by the latter in the reciprocation thereof, said offset cylinder including a resilient compressible offset blanket rollingly engageable with the form and compressible during said engagement to compensate for differences in the height of the printing surfaces on said form,

means for inking said form in the reciprocation of the bed, said offset surface and form traversing said offset and impression cylinders respectively in the order named on the printing stroke, means controlled by the reciprocation of said bed for elevating the offset cylinder out of engagement with the offset surface and for positioning the impression cylinder for rolling engagement of a sheet thereon with said ofi'set surface on said printing stroke, means controlled bythe reciprocation of the bed for elevating the impression cylinder relative thereto out of engagement with said offset surface during the return stroke, and means for raising and lowering said offset cylinder relative to the bed to successively receive an impression from the form and transfer the same to said surface on one stroke, and to miss contact with said surface on the other stroke, whereby a complete printing cycle is performed in the printing and return strokes, said offset cylinder receiving an impression from the form and transferring said impression to said offset surface, the sheet on said impression cylinder receiving an impression from said surface on the printing stroke.

6. In a printing machine for printing offset impressions from a relief printing form, in combination with a printing form of the above type and an offset surface, a rotatable sheet carrying impression cylinder and a rotatable transfer cylinder, means for reciprocating said form and surface relative to said cylinders successively on opposite printing and return strokes, means for inking said form, said offset surface and form traversing said offset and impression cylinders respectively in the order named on the printing stroke, means for relatively shifting the offset cylinder out of engagement with the offset surface and for relatively positioning the impression cylinder for rolling engagement of a sheet thereon with said offset surface on said printing stroke, means for relatively shifting the impression cylinder out of engagement with said offset surface during the return stroke, and means for raising and lowering saidoifset cylinder relative to the bed to successively receive an impression from the form and transfer the same in said surface on one stroke. and to miss contact with said surface on the other stroke, whereby a complete printing cycle is performed in the printing and return stroke, said offset cylinder receiving an impression from the form and transferring said impression to said offset surface, the sheet on said impression cylinder receiving an impression from said surface on the printing stroke.

7. In a bed and cylinder machine having a frame supporting a bed and cylinder carriage reciprocable relative to each other, a relief type form and a flat oflset surface on said bed in spaced relation to one another longitudinally of the direction of reciprocation, an offset cylinder rotatably mounted on said carriage having a resilient offset surface thereon engageable with said form and bed offset surface in one direction of relative reciprocation 0f the bed and carriage, means for automatically varying the paths of travel of said offset cylinder and bed relative to each other during each work cycle of movement thereof, whereby to pick up an impression from said form and transfer the same to said bed offset surface, and an impression cylinder rotatably mounted in said carriage and engageable with said bed offset surface only in the opposite relative direction of relative reciprocation, said impression cylinder having means to secure a sheet thereon whereby the sheet picks up an impression from said bed offset surface.

8. In a bed and cylinder machine having a pair of printing member supports simultaneously operable in opposite directions, a flat relief type form and a flat transfer surface mounted in spaced relation to one another on one of said supports, a rotary oflset surface and a rotary sheet carrying member on the other support, said offset surface being successively engageable with said form and transfer surface in the relative movement of said supports to pick up an impression from said form and transfer the same to said transfer surface. said sheet carrying member engaging a sheet thereon with said transfer surface whereby said sheet picks up an impression from said transfer surface, and means synchronized with the relative movement of said supports for efiecting engagement of said rotary offset surface with said flat form and flat transfer surface in one stroke of the form and transfer surface and disengagement thereof in the opposite stroke and for effecting engagement of said rotary sheet carrying member with said flat transfer surface in one stroke of said transfer surface and disengagement in the opposite stroke.

9. In a bed and cylinder machine having a pair of printing member supports simultaneously operable in opposite directions, a fiat relief type form and a flat transfer surface mounted in spaced relation to one another on one of said supports, a rotary offset surface and a rotary sheet carrying member on the other support, said offset surface being successively engageable with said form and transfer surface in the relative movement of said supports to pick up an impression from said form and transfer the same to said transfer surface, said sheet carrying member engaging a sheet thereon with said transfer surface whereby said sheet picks up an impression from said transfer surface.

CHARLESLIDW.

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